MPQ8903 – LOW DROPOUT, 150mA LINEAR REGULATOR

MPQ8903 Rev. 1.2

www.MonolithicPower.com

7

5/21/2010

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PCB layout guide

PCB layout is very important to achieve good

regulation, ripple rejection, transient response

and

thermal

performance.

It

is

highly

recommended to duplicate EVB layout for

optimum performance.

If change is necessary, please follow these

guidelines and take figure 5 for reference.

1) Input and output bypass ceramic capacitors

are suggested to be put close to the IN Pin

and OUT Pin respectively.

2) Ensure all feedback connections are short

and direct. Place the feedback resistors and

compensation components as close to the

chip as possible.

3) Connect IN, OUT and especially GND

respectively to a large copper area to cool

the chip to improve thermal performance and

long-term reliability.

MPQ8903DJ

FB

OUT

4

5

GND

2

EN

IN

3

1

OUTPUT

C3

C2

C1

R3

R1

R2

C1

1

2

34

5

VIN

EN

GND

FB

OUT

C3

VIN

VOUT

GND

R1

R2

C2

C3

R3

Top Layer

Figure 3—PCB Layout